3.4 Equations of Lines What’s the purpose? Finding: - Slope-Intercept Form of a Linear Equation (today) & -Standard Form of a Linear Equation How/why/to what does it relate? Copyright © 2008 Pearson Education, Inc. Publishing as Pearson Addison-Wesley

Equation of a line in slope intercept form (y = mx+b) Now that we know how to find slope given any two points, we can generate an equation of the line connecting the two points. Example : points (3,2) and (6,9)

Part I – Finding m Determine the slope of the line that contains the given points. 1. (-2,3) and (5,6)2. (1, -7) and (1,4) * Use the slope formula m = ?m = ? Copyright © 2008 Pearson Education, Inc. Publishing as Pearson Addison-Wesley

Part II – finding b Find b (from the equation y = mx + b) by substituting one of the points back into the equation. 1. (-2,3) and (5,6)2. (1, -7) and (1,4) b = ? b = ? Now, substitute your m and b values into the slope – intercept equation (y = mx + b). Copyright © 2008 Pearson Education, Inc. Publishing as Pearson Addison-Wesley

Part III – putting m and b into equation form Hint: Identify m and b, then substitute into the slope – intercept equation (y = mx + b)

Assignment Pg #2-44 (evens) Copyright © 2008 Pearson Education, Inc. Publishing as Pearson Addison-Wesley